Peak sun hours – Why the difference?
Kawu Musa Idris-Idah, 27th October 2024 Introduction In simple terms, “Peak sun hours (PSH)” quantifies the average number of hours in a day during which the sun’s intensity is greater than or equal to 1000 W / m2 (Watt per Square Meter). It serves as the foundation for solar energy design. The sun is considered “restless” because it always emits electromagnetic radiation that journeys to earth. Akin to the sun, the earth restlessly rotates on its axis. One earth rotation is completed every 24 hours. As the earth rotates, half of it faces the sun: regions facing the sun then experience “daytime”. Other regions not facing the sun, experience “nighttime”. Albeit a group of regions facing the sun at the same time, the intensity of the sun’s radiation is not equally distributed across all these regions. Some regions may experience more radiation than others. Potential reasons include the presence / absence of clouds in different regions, quality of air within a region. Essentially, the journey of sunlight (electromagnetic rays) from the sun to the earth isn’t a direct one. The atmosphere and the distance between the sun are examples of barriers that could reduce sunlight intensity. And so what? The introduction explains why sunlight intensity in Kaduna at 11 am is different from Imo’s intensity at 11 am, albeit being in the same country. According to https://power.larc.nasa.gov/data-access-viewer/, Kaduna and Imo get 4.47 and 3.77 peak sun hours in a day respectively. Case in point, Mr. A’s house in Imo and Miss B’s house in Kaduna have exactly the same equipment type and usage pattern. Assuming daily energy consumption in both houses is 2.5 kWh (Kilowatt-hour): calculations show that 1 more panel is needed at Imo for Miss B’s equipment to function as Mr. A’s would. The cost of Miss B’s installation would therefore be higher by the added cost of a solar panel, all things being equal.